Instruments for the manipulation of dangerous liquids



April 19, 1960 A. KASPAUL 2,932,974

INSTRUMENTS FOR THE MANIPULATION OF DANGEROUS LIQUIDS Filed Aug. 3, 1956 179.2 Hg 179.4 E95 //Vl/f/Y70,Q 098.60 (950901.

United States Patent INSTRUMENTS FOR THE MANIPULATION OF DANGEROUS LIQUIDS Alfred Kaspaul, Veyrier-Geneva, Switzerland, asslgnor to Paul Vogel, Geneva, Switzerland Application August 3, 1956, Serial No. 601,979 Claims priority, application Switzerland August 5, 1955 8 Claims. (Cl. 73425.6)

Instruments are already in existence for the manipulation of dangerous liquids, especially radio-active liquids, comprising a pipette, a support for said latter and a pump for enabling liquid to be drawn into the pipette. In general, said instruments have certain dangers, as the pipette is secured to its support by clamping members and the user is obliged to touch the pipette when he desires to remove it from the support. There thus exists a serious danger of coming into contact with the radio-active liquid. Further, aspiration of the liquid into said pipettes is elfected by means of a pump secured to the support, near the place occupied by the operator. This pump is connected to the pipette by a flexible tube and when the operator makes too strong an aspiration by means of the pump, the radio-active liquid may penetrate into the flexible tube and even reach up to the pump. Under these conditions it is practically impossible subsequently to separate the flexible tube from the pipette without being in direct contact with the radio-active liquid which has penetrated into the tube.

The invention has for its subject to remedy the above disadvantages. It has for its subject an instrument of the type referred to wherein the pipette is integral with a conical part adapted to be engaged in a recess of conical shape corresponding with the support, at least an opening being provided in the conical part of the pipette so as to cause the interior thereof to communicate with a passage provided in the support and leading to the pump.

In the accompanying drawing are shown diagrammatically and by way of example a form of construction of the instrument forming the subject of the invention and a number of forms of construction of pipettes for said instrument.

Fig. 1 is a diagrammatic section of the instrument and Figs. 2 to 6 show various pipettes capable of being secured to the support shown in Fig. l.

The instrument shown in Fig. 1 comprises a long tube 1, which has been broken away in the drawing for greater convenience but which, in reality, may have a length of 1 to 2 m. One end of said tube is partly engaged in a cylindrical recess 2 of a removable part 3. A part of the wall of said recess 2 has a slot 4 and a conical outer screw thread 5, enabling this wall to be tightened by means of a milled screw 6 for ensuring the fixing of the part 3 on the end of the tube 1.

The cylindrical recess 2 forms the chamber of a pump and contains a sliding piston 7, secured to one end of a rod 8 passing through the tube 1. The other end of said rod 8 carries a handle 9 through the medium of which the operator can communicate the desired movements to the piston 7. The part 3 is also provided with a recess 10 of conical shape in which is provided an annular groove 11 communicating by means of a passage 12 with the chamber of the pump.

The pipette is formed by two receptacles 13 and 14, fitted one within the other. The receptacle 14 is extended downwards by a tube 15 forming the neck of the pipette. The receptacle 13 has at its lower part a conical part 16 of a shape corresponding with a conical recess 10 of the part 3. The base of the conical part 16 is connected to the tube 15 by a tubular wall 17 in such a manner that a space 18 is provided between the tube 15 and the wall 17. The upper wall of the receptacle 14 has an orifice 19 placing it in communication with the receptacle 14. The upper part of said latter has an orifice 20 closed by a knob 21.

The conical part 16 has at least an opening 22 whereby the receptacle 13 communicates with the chamber of the pump through the medium of the groove 11 and the passage 12.

The operation of said instrument is very simple, as it suffices for the user to manipulate the handle 9 of the rod 8 to suck or blow air into the interior of the receptacle 14 of the pipette. Said air passes through the passage 12, the groove 11, the opening 22, the receptacle 13 and the orifice 19. If, inadvertently, the operator sucks too large a quantity of liquid into the receptacle 14, said liquid will pass out through the orifice 19 and flow along the outer wall of the receptacle 14. Said liquid will fill the space 18 which forms an overflow, whereby the operator is enabled to notice his error in manipulation, as, as will be understood, all the parts of the pipette are of transparent material, for example glass, with the exception of the plug 21, which may be of rubber. In order to avoid that a possible excess of liquid may penetrate into the interior of the pump, the opening 22 provided in the conical part 16 has a collar 23, projecting into the interior of said part; in this manner, liquid eventually flowing along the inner wall of the receptacle 13 is deviated and cannot pass through the opening 22.

The wall of the receptacle 13 is deformed at its upper part so as to form bearing points 24 for the receptacle 14. Said latter has a scale 25, enabling the quantity of liquid sucked into the pipette to be measured. It is also possible to provide a scale on the wall 17 so as to enable, it necessary, the quantity of liquid in the overflow, by reason of an error in manipulation, to be measured.

When the operator has completed his operation when he desired to use another pipette, he can easily remove the pipette secured to the end of the support in the part 3, by pressing the neck of the pipette against an object and moving the support downwardly, whereby the two conical parts 10 and 16 are disengaged. It is thus easy to avoid any direct contact of the hands with the pipette which sometimes still contains drops of radio-active material.

The orifice 20, closed by a plug 21, is provided for facilitating the cleaning of the pipette after use. Said orifice is, however, not indispensable.

It is naturally possible to provide numerous forms of construction of the pipette and Figs. 2 to 6 give some examples.

In the pipette shown in Fig. 2, the receptacle 14 is extended downwards by a tube 15 passing into the interior of the conical part 16 and forming the neck of the pipette. The upper part of the receptacle 14 is placed in communication with the interior of the part 16 by a bent tube 26 passing to the outside of the receptacle 14. The lower end of said tube 26 projects into the interior of the conical part 16 and is so directed that an eventual excess of liquid flows directly into the space forming the overflow without being capable of reaching the opening 22 of the conical part which does not have a collar as in Fig. 1.

Fig. 3 shows a pipette of the same type as that shown in Fig. 'l, but in which an annular wall 27 is provided so as to prevent the liquid in excess from reaching the opening 22.

The pipette shown in Fig. 4 is distinguished from the preceding ones by the fact that the tube 15 does not pass through the conical parts 16. Said part 16 is simply connected to a pipette of the usual type by a bent tube 28. A force arm 29 is welded between the receptacle 14 of the pipette and the upper face of the conical part 16 so as to increase the rigidity of the assembly.

Fig. 5 shows a very simple form of construction in which the receptacle 14 of the pipette is secured underneath the conical part 16. Said pipette is not provided with an overflow for containing an eventual excess of liquid in the case of defective manipulations.

Fig. 6 shows another pipette of the same type as that shown in Fig. 5, but in which a space 18, forming an overflow, is comprised between the bottom of the wall of the conical part 16 and a tube 30 extending the upper wall of the receptacle 14.

I claim:

1. A pipette for handling dangerous liquids such as radioactive liquids, comprising, in combination, an elongated receptacle, a hollow member defined by a wall in the shape of a truncated cone, said hollow member being in operative, tortuous communication with said elongated receptacle, whereby liquid can overflow from said receptacle into said hollow member, said wall in the shape of a truncated cone having at least one opening therethrough, a support member having a recess in the shape of a truncated cone, said hollow member defined by the wall in the shape of a truncated cone being removably positioned in said support member in said recess in the shape of a truncated cone, said support member having an annular groove in the wall of said recess, a conduit in said support member, said conduit being in communication with said annular groove, said annular groove being in communication with said hollow member at said opening through said wall thereof, and a pump connected to said conduit, whereby a radioactive liquid can be drawn into said receptacle by operating said pump, whereby the overflow of radioactive liquid from the receptacle will be received by said hollow member, thereby preventing contact of said radioactive liquid with the operator, and whereby said receptacle and hollow member can be removed from said support member without requiring the operator to contact said radioactive liquid with his hands.

2. A pipette for handling dangerous liquids such as radioactive liquids, comprising, in combination, an elongated receptacle, a hollow member defined by a wall in the shape of a truncated cone, said receptacle being positioned for at least a portion thereof within said hollow member, said hollow member being in operative, tortuous communication with said elongated receptacle, whereby liquid can overflow from said receptacle into said hollow member, said wall in the shape of a truncated cone having at least one opening therethrough, a support member having a recess in the shape of a truncated cone, said hollow member defined by the wall in the shape of a truncated cone being removably positioned in said recess in the shape of a truncated cone, said support member having an annular groove in the wall of said recess, a conduit in said support member, said conduit being in communication with said annular groove, said annular groove being in communication with said hollow member at said opening through said wall thereof, and a pump connected to said conduit, whereby air can be withdrawn from said conduit, said annular groove, said hollow member, and said elongated receptacle thereby allowing radioactive liquid to enter said elongated receptacle without contacting the operator and whereby said receptacle and hollow member can be removed from said support member without requiring the operator to contact said radioactive liquid with his hands.

3. A pipette for handling dangerous liquids such as radioactive liquids, comprising, in combination, an elongated receptacle, a hollow member defined by a wall in the shape of a truncated cone, said hollow member being in operative, tortuous communication with said elongated receptacle, whereby liquid can overflow from said receptacle into said hollow member, said wall in the shape of a truncated cone having at least one opening therethrough, a support member having a recess in one end thereof in the shape of a truncated cone, said hollow member defined by the wall in the shape of a truncated cone being removably positioned in said support member in said recess in the shape of a truncated cone, said support member having an annular groove in the wall of said recess, a conduit in said support member, said conduit being in communication with said annular groove, said annular groove being in communication with said hollow member at said opening through said wall thereof, said support member including a tubular member at the other end thereof, whereby an operator can hold said support, the longitudinal axis of said recess in said support at the end thereof being perpendicular to the longitudinal axis of said tubular member, and a pump connected to said conduit, whereby air can be withdrawn from said conduit, said annular groove, said hollow member, and said elongated receptacle thereby allowing radioactive liquid to enter said elongated receptacle without contacting the operator and whereby said receptacle and hollow member can be removed from said support member without requiring the operator to contact said radioactive liquid with his hands.

4. The pipette of claim 3 wherein said pump comprises a rod member positioned in said tubular member, a piston head fixed to said rod member at one end thereof adjacent to said conduit, at an opening thereof, and a pump handle fixed to said rod member at the other end thereof.

5. The pipette of claim 1 including another hollow member in operative, direct communication with said first named hollow member,- whereby said overflow radioactive liquid passes from said first named hollow member to said other hollow member.

6. The pipette of claim 1 including a tubular member open at its respective ends extending through the topmost portion of the wall of said elongated receptacle at one end thereof and through the wall of the hollow member at the other end thereof, at the portion of the hollow member substantially closest to said topmost portion of said receptacle wall.

7. A pipette for handling dangerous liquids such as radioactive liquids, comprising, in combination, a first elongated receptacle having an opening through its uppermost wall portion and an open tubular elongated hollow neck portion depending from its bottom wall portion, a second elongated receptacle positioned about and spaced from said first receptacle, said second receptacle having a closed top portion, a truncated cone-shaped hollow member contiguous with and depending from said second receptacle at its lower portion, said hollow member being positioned about and spaced from said neck portion, another hollow member contiguous with and depending from the bottom portion of said truncated cone-shaped hollow member, said other hollow member being positioned about and spaced from said neck portion and fixedly secured to the lower portion of said neck portion adjacent its opening, whereby liquid can overflow from said first receptacle through said opening through its uppermost wall portion into said truncated cone-shaped hollow member and then into said other hollow member, said truncated cone-shaped hollow member having at least one opening therethrough at its wall, a support member having a truncated cone-shaped recess, said truncated coneshaped hollow member being removably positioned in said truncated cone-shaped recess of said support member, said support member having an annular groove in the wall of said recess, a conduit in said support member, said conduit being in communication with said annular groove, said annular groove being in communication with said truncated cone-shaped hollow member at said opening through its wall, a pump connected to said conduit, whereby air can be withdrawn from said conduit, said annular groove, said hollow members, and said receptacle thereby allowing radioactive liquid to enter said first elongated receptacle without contacting the operator and whereby said receptacle and hollow members can be removed from said support member without requiring the operator to contact said radioactive liquid with his hands.

8. The pipette of claim 7 including a collar positioned about said opening through the wall of said truncated cone-shaped hollow member, said collar projecting into the interior of said truncated cone-shaped hollow memher, whereby liquid flowing into said hollow member is prevented from passing through said opening.

References Cited in the file of this patent UNITED STATES PATENTS 553,044 Sharples Ian. 14, 1896 1,433,075 Gottlieb Oct. 24, 1922 2,158,102 Betzold May 16, 1939 FOREIGN PATENTS 476,661 Great Britain 1938 1,025,614 France Jan. 28, 1953 

